St Day was a place of pilgrimage prior to the Reformation when there was a chapel dedicated to the Holy Trinity, situated in the area occupied by Trinity House at West End and the adjacent Trevean Cottages in Buckingham Place.

St Day was the commercial centre of the Gwennap Mining Area and with Carharrack and Lanner was part of the Gwennap Ecclesiastical Parish until 1835 when St Day became a separate parish.

Prior to the dedication in 1828 of the now closed OldChurch burials took place at Gwennap. Worship now takes place in the converted Sunday School on the opposite side of the road.

In the Old Church there are extensive interpretive boards which give an insight into the history of the area. There are also memorials on the walls and an impressive memorial statue. The OldChurch is open through the summer months.

The tops of the iron railings at the entrance to the Churchyard and the railings around most graves were removed to aid production of munitions in World War II.

The decline of mining after 1850 led to the widespread emigration to various parts of the world and several headstones record the death of a loved one abroad.

There are several graves of servicemen killed in the two wars. One of these is unusual in that it commemorates two soldiers.

Down the right of the OldChurch are the large flat topped tombs of the Harvey family who were merchants supplying the mines of the area as well as the general public.

To the east of the church enclosed by railings is the tomb of the Hawke family who owned a rope works at Tregunlow.

To the north of the church is the large grave of the Corfield family who ran a chemists shop in Church Street for several generations. Their descendants are buried just in front of the Hawke family's tomb.